Mass Casualty Incident Management

Mass casualty incident management is the approach to events in which the number of casualties exceeds the resources immediately available, forcing a shift from doing everything possible for each individual to doing the greatest good for the greatest number. Its central tool is rapid triage: sorting many patients quickly into priority categories so that limited people, supplies, and transport are used where they can save the most lives.

Definition

Mass casualty incident management is the coordinated process of triaging, treating, and transporting casualties when demand exceeds available resources, using rapid sorting systems to assign treatment and evacuation priorities so as to maximise overall survival.

Scope

This topic covers the logic of mass-casualty triage and the systems built on it, including the START method and the SALT national guideline framework, the colour-coded priority categories used to sort casualties, and how mass-casualty triage differs from everyday field triage. It is reference methodology and policy material; it does not provide operational triage instructions or treatment direction for any individual.

Core questions

• How does mass-casualty triage differ from routine field triage?
• What rapid sorting logic underlies systems such as START and SALT?
• What do the standard priority categories represent?
• How are different mass-casualty triage systems evaluated and compared?

Key concepts

• Resource-limited triage and the greatest good for the greatest number
• START (Simple Triage and Rapid Treatment)
• SALT (Sort, Assess, Lifesaving interventions, Treatment/Transport)
• Priority categories (immediate, delayed, minimal, expectant, dead)
• Global sorting then individual assessment
• Sensitivity and specificity of triage systems
• Reverse-triage logic in scarce-resource conditions

Mechanisms

Mass-casualty triage replaces individualised care with rapid, repeatable sorting. The START method uses quick assessments of the ability to walk, respiratory status, perfusion, and mental status to assign casualties to colour-coded priority categories in seconds. The SALT framework adds an initial global sort, followed by individual assessment with limited lifesaving interventions, and assigns immediate, delayed, minimal, expectant, or dead categories; it was proposed as a national evidence-based guideline (Lerner, 2008). These systems are evaluated by how accurately they classify casualties relative to a reference standard, with studies comparing the sensitivity and specificity of START and SALT (Bhalla, 2015). Mass-casualty triage interfaces with the wider trauma system and routine field-triage criteria once resources are no longer overwhelmed (Newgard, 2022).

Clinical relevance

Mass-casualty triage methods shape disaster planning, drills, and emergency-system policy, and they provide the framework researchers use to study how casualties are sorted under scarcity. Understanding them helps a reader interpret evaluations of triage accuracy and disaster response. This entry describes the systems and the evidence about them; it is not an operational triage protocol and does not direct the categorisation or treatment of any individual casualty.

Epidemiology

Mass-casualty events range from transport crashes to natural disasters and intentional attacks, and the performance of triage systems is studied largely through simulations, exercises, and retrospective analyses because real events are infrequent and heterogeneous. Comparative studies report differing sensitivity and specificity across systems, and accuracy can vary with casualty population and assessor training (Bhalla, 2015).

History

Triage as deliberate prioritisation of casualties has military origins, and modern civilian mass-casualty triage was systematised in the late twentieth century with rapid field methods such as START. To reduce the proliferation of incompatible local schemes, a national working group reviewed the evidence and proposed the SALT framework as a unifying guideline (Lerner, 2008). Subsequent comparative research evaluated the accuracy of competing systems (Bhalla, 2015), and mass-casualty triage was situated alongside revised everyday field-triage guidance (Newgard, 2022).

Debates

Which mass-casualty triage system performs best?

Systems such as START and SALT use different sorting logic and yield different sensitivity and specificity, so no single method is unambiguously superior across all casualty populations; the choice involves trade-offs between speed, over- and under-categorisation, and ease of training, and is studied mainly through simulation.

Key figures

• E. Brooke Lerner
• Richard B. Schwartz
• Manish C. Bhalla

Seminal works

• lerner-2008-salt
• bhalla-2015

Frequently asked questions

How does mass-casualty triage differ from everyday triage?

In everyday care, resources are sufficient and the sickest patient is treated first. In a mass-casualty incident, demand exceeds resources, so triage shifts to sorting many patients rapidly into priority categories to maximise overall survival, which can mean deferring care for those least likely to benefit.

What do the colour categories in mass-casualty triage mean?

Most systems sort casualties into priority groups commonly labelled immediate (red), delayed (yellow), minimal (green), expectant (often grey or black), and dead. The categories reflect urgency and likelihood of benefit given the available resources, and they guide the order of treatment and transport rather than a fixed treatment.